The invention relates to a small sized fan motor and more particularly relates to a mechanism of the fan motor including a single rotational bearing supporting a rotor and a fan having a plurality of blades resulting in reduction of the axial dimension of the motor.
So far the conventional small sized fan motors have been of a brushless outer rotor type using Hall generators or Hall IC. As described in the publication "DC Servo-Motors for Mechatronics" the third edition published by the publisher Sogo Denshi of Japan, such a conventional small sized fan motor has a center shaft rotated with a rotor, the center shaft being supported by a pair of rotational bearings and having a fan secured thereto. With such a structure being provided, it is inevitable that the motor is accordingly elongated in the axial direction. Therefore the conventional small sized fan motor has been unsuitable to be used in a small sized electronic apparatus, especially in a thinner apparatus. Even in the conventional brushless outer rotor type of motor without using a center shaft, a pair of rotational bearings are employed in the axial direction of the motor resulting in limitation of reducing the axial dimension of the motor. More precisely these conventional small sized fan motors as mentioned above have the axial dimension about 24 mm-25 mm at least.